Mechanical property evaluation of thin film metallic glasses via molecular dynamics and finite element analyses

Abstract

This study presents a method for extracting free-volume model (FVM) parameters of Zr-based thin film metallic glasses (TFMG) using the molecular dynamics (MD) and finite element analyses (FEA). Nano-tension MD simulations are performed to obtain the first two elastic properties of thin film, i.e., Young's modulus and Poisson's ratio. The other two main FVM parameters (reference stress and pressure dependent coefficient) are determined by systematically matching FE stress-strain curves to those from MD analyses with the finite element model updating (FEMU) method. Nanoindentation FEA and experiments are performed with Zr-based TFMG specimens to validate the estimated FVM parameters. It demonstrates that the combined MD/FEA approach is not only simpler, but also more efficient than previous methods in obtaining all primary parameters.